It is well known and established that performance characteristics associated with electronic, electromechanical and mechanical devices may be affected by both temperature and humidity. Low temperatures affect the operation of electrical and electronic components. Switches, printed circuit boards and the like become brittle at low temperatures, while the functional characteristics of components and the circuits are affected by temperature. While temperature compensation techniques are known, many systems do not lend themselves to the economical incorporation of such compensation. Other systems are simply not of the type in which temperature compensation can be easily accommodated.
On the mechanical side, temperature variation, and particularly low temperatures, often impair the efficiency of lubricants, as well as the elasticity of mounts and springs; the physical contraction of components associated with decreasing temperature may also lead to operational variability or inoperativeness. Once again, while techniques may exist for compensating for such temperature effects, such compensation is not always appropriate or economical.
Humidity is also a factor which can deleteriously affect operation, particularly when associated with temperature fluctuations. The combination of falling temperature in a high humidity environment can result in condensation upon environmental surfaces, such as switch contacts, linkages and other operating elements, can lead to corrosion. In addition, the presence of moisture on electronic components, leads and contacts can lead to shorting and changes from the intended values of circuit components.
The foregoing problems are especially acute in connection with switchgear and other apparatus which are typically housed in non-insulated enclosures, located outdoors, which primarily provide only a physical barrier about the equipment for safety and protection purposes.
It is accordingly a purpose of the present invention to provide an environmental control apparatus particularly adapted to allow control and modification of environmental characteristics within an environmental space, such as may be defined by the interior of an enclosure.
A further purpose of the present invention is to provide such an apparatus which allows control of both temperature and humidity conditions.
Still a further purpose of the present invention is to provide such an apparatus which may be programmed and adjusted to maintain temperature and humidity levels within an environmental volume within preset limits which can be optimized for the equipment located within the environment.
Yet a further purpose of the present invention is to provide an apparatus of the aforementioned type which is of compact and economical construction, and which does not constitute a safety or fire hazard.